A057190 Numbers k such that (24^k+1)/25 is a prime.

7, 11, 19, 2207, 2477, 4951, 821497

Offset: 1

Author

N. J. A. Sloane, Sep 15 2000

Keywords

• nonn
• more

Comments

a(7) > 10^5. - Robert Price, Jun 04 2013

Links

• H. Dubner and T. Granlund, Primes of the Form (b^n+1)/(b+1), J. Integer Sequences, 3 (2000), #P00.2.7.
• H. Lifchitz, Mersenne and Fermat primes field

Programs

PARI

isok(n) = (denominator(p=(24^n+1)/25)==1) && isprime(p); \\ Michel Marcus, Oct 30 2017

Extensions

a(7) from Paul Bourdelais, Jan 06 2025